selftests/bpf: Test packet range of pointers sharing an idgrafted

Add tests where two packet pointers share an id and tightening one
pointer's umax from its var_off would put it less than their constant
distance from the other's umax: with an index & 0x38 capped at 50, the
base pointer keeps umax 50, so the pointer 8 bytes further on must keep
umax 58, even though its known bits allow at most 56.

These refused a valid program or accepted an out-of-bounds access before
the fix:

- check the advanced copy, load through the base: valid, was refused;
- check the base, load the byte at base + 1 through a copy advanced by
  8: was accepted;
- check base + 4, load 4 bytes at base + 2 through base + 8: reads two
  bytes past the checked range, was accepted;
- the same as the second with data_meta pointers checked against data:
  was accepted.

These pass with and without the fix and cover nearby paths:

- subtract an unknown scalar from a checked pointer and load below it
  (the range is kept across a new id);
- reach a load through two paths whose checks cover 8 and 7 bytes after
  the loaded pointer; the second path must not be pruned by the first;
- spill a copy of a pointer, check the pointer, fill the copy and load
  one byte past the checked range: the load is refused, and the copy
  has the range of the check.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20261001145255.855630-2-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 49 insertions, 0 deletions

diff --git a/scripts/min-tool-version.sh b/scripts/min-tool-version.sh
new file mode 100755
index 000000000..99bfdcaa3
--- /dev/null
+++ b/scripts/min-tool-version.sh
@@ -0,0 +1,49 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Print the minimum supported version of the given tool.
+# When you raise the minimum version, please update
+# Documentation/process/changes.rst as well.
+
+set -e
+
+if [ $# != 1 ]; then
+	echo "Usage: $0 toolname" >&2
+	exit 1
+fi
+
+case "$1" in
+binutils)
+	echo 2.30.0
+	;;
+gcc)
+	if [ "$ARCH" = parisc64 ]; then
+		echo 12.0.0
+	else
+		echo 8.1.0
+	fi
+	;;
+llvm)
+	if [ "$SRCARCH" = loongarch ]; then
+		echo 18.0.0
+	else
+		echo 17.0.1
+	fi
+	;;
+rustc)
+	if [ "$SRCARCH" = "s390" ]; then
+		echo 1.96.0
+	elif [ "$ARCH" = powerpc ]; then
+		echo 1.95.0
+	else
+		echo 1.85.0
+	fi
+	;;
+bindgen)
+	echo 0.71.1
+	;;
+*)
+	echo "$1: unknown tool" >&2
+	exit 1
+	;;
+esac